Potassium Iodide

Iodine

Essential mineral for thyroid function. Also used for thyroid protection in radiation emergencies.

Part of Iodine mineral
Compare all forms

Typical dose

For iodine deficiency/nutritional supplementatio...

Oral Oral safety: low

About this supplement

Potassium iodide is an inorganic ionic compound consisting of potassium cations (K⁺) and iodide anions (I⁻). It is the most common form of supplemental iodine, an essential trace mineral. In the body, iodide is rapidly absorbed and concentrated in the thyroid gland, where it is incorporated into the thyroid hormones thyroxine (T4) and triiodothyronine (T3), which regulate metabolism, growth, development, and numerous cellular processes. Potassium iodide is also used in emergency situations (e.g., nuclear accidents) to saturate the thyroid with stable iodine, blocking the uptake of radioactive iodine isotopes and reducing the risk of thyroid cancer. It is typically administered orally as tablets, solution (SSKI - saturated solution of potassium iodide), or as a component in multivitamin/mineral supplements.

How much to take

Typical amount
For iodine deficiency/nutritional supplementation: Typically 150-290 mcg iodine (as KI) daily for adults. For thyroid blocking in radiation emergencies: Dosage varies by age (e.g., adults 130 mg KI, children lower doses) as a single dose or repeated per public health guidance.
Suggested range
Nutritional: 150-290 mcg iodine (as KI) daily. Emergency (radiation): 16-130 mg KI as a single dose, depending on age.

Potential benefits

Benefits linked to this supplement form:

Thyroid Health

Research strength: Very strong

 Metabolism

Research strength: Strong

 Thyroid Hormone Synthesis

Research strength: Very strong

 Prevention of Iodine Deficiency Disorders

Research strength: Very strong

 Fetal and Infant Neurodevelopment

Research strength: Very strong

 Topical Antiseptic

Research strength: Very strong

 Thyroid Protection from Radioactive Iodine

Research strength: Very strong

 Support for Normal Metabolism and Growth

Research strength: Very strong

Things to watch for

Possible side effects linked to this form:

Thyroid Dysfunction

How serious: Moderate

 Allergic Reactions

How serious: Mild

 Gastrointestinal Distress

How serious: low

 Iodine-Induced Hyperthyroidism

How serious: high

 Hypothyroidism

How serious: medium

 Metallic Taste, Nausea, GI Upset

How serious: low

 Topical Skin Irritation

How serious: low

 Metallic Taste, Sore Teeth/Gums

How serious: low

Health goals

Needs and goals this form may help with:

Other forms of Iodine

Compare absorption and active amounts with sibling forms:

Kelp (Seaweed)

Rich natural source of iodine and minerals. Supports thyroid health.
Molecular Iodine (I2)

Powerful antiseptic; essential mineral for thyroid function.
Nascent Iodine

A supplemental form of iodine claimed to be in a highly bioavailable atomic stat...
Sodium Iodide

Essential mineral for thyroid function and metabolism.
Compare all forms in the table
Technical details ▼

Chemical ID (CAS)

7681-11-0

Formula

KI

Physical properties

White crystalline powder or colorless cubic crystals. Odorless with a bitter, saline taste. Highly soluble in water, glycerol, and ethanol. Hygroscopic (absorbs moisture from air). Density: 3.13 g/cm³. Melting point: 681°C.

How it’s made

Primarily produced synthetically by reacting potassium hydroxide (KOH) or potassium carbonate (K₂CO₃) with hydriodic acid (HI). Alternatively, by reacting iodine with hot potassium hydroxide solution, which forms potassium iodide and potassium iodate, followed by reduction of the iodate to iodide.